Qt Creator 3.0.0 and Ctrl-Shift under X.Org X Server 1.15.0

I'm running Arch Linux with X.Org server 1.15.0 and I have Qt Creator 3.0.0 with Qt 5.2.0 installed from Arch repo.
I'm using Awesome window manager.
I'm using the following Xorg keyboard configuration:
@Section "InputClass"
Identifier "system-keyboard"
MatchIsKeyboard "on"
Option "XkbLayout" "us,ru"
Option "XkbVariant" ","
Option "XkbOptions" "grp:ctrl_shift_toggle,grp_led:scroll,compose:rwin"
EndSection
@
The problem is the following: whenever I use ctrl+shift to change keyboard layout, Qt creator loses the first key I press.
For example, if i keep pressing the same key (for example, "G") twice then switch layout, press it twice again, switch, press, etc., I get "пgпgпgпg" instead of "ппggппggппggппgg", because every key right afrer layout change is "eaten".

I've found the following: this happens if "grp:ctrl_shift_toggle" was set during Qt Creator startup. If it's started, and then I switch layout change to Alt+Shift:
@setxkbmap -option -option grp:alt_shift_toggle
@
then Qt Creator still "eats up" the first key after Ctrl+Shift released.
If Qt creator is started with "grp:with alt_shift_toggle" or with no toggle at all, everything is fine even if I switch to "grp:ctrl_shift_toggle" after it's start.

The problem doesn't seem to appear in Gnome DE, as long as it uses his own layout management routine, but I don't like new gnome, so I decided to stay in Awesome.
Any other app works fine.
Awesome doesn't use any "Ctrl+Shift+KEY" sequences. All his shortcuts involve a key with a logo between Ctrl and Alt.

I'm not sure if this is a bug of Qt creator or my own distro setup, so I've posted it here and not in the bugtracker.

Something is really funny...
Ctrl+Num/ doesn't seem to work, while Ctrl+'/' (where '/' is located on the left from Right Shift key) works.
This is independant of NumLock or current layout and sometimes is very frustrating.

OK. Brilliant. Now Qt creator is completely unusable.
With version 3.1.2 my workaround doesn't work anymore. Qt creator keeps eating up the first symbol after Ctrl+Shift language switch. If I change grp:ctrl_shift_toggle to grp:alt_shift_toggle, Ctrl+Shift doesn't produce any bugs but doetn't switch layout as well.